"In the initial interrogation, Rajendra has accepted that he planted improvised explosive devices (IEDs) in the Samjhauta train and Meeca Masjid in Hyderabad. He was active in Rashtriya Swayamsevak Sangh (RSS) in Hatod of Madhya Pradesh," a source said.

Investigators believe that Rajendra's further questioning can lead them to a senior functionary of RSS who has been under scanner of the agency in connection with the larger conspiracy to carry out bomb blasts in mosques and places frequented by Muslims in retaliation of jehadi terrorism. The senior RSS functionary runs many outfits in Jammu.

Sunil Joshi, an RSS pracharak and the kingpin of gang of right-wing extremists that planted bombs all over India, had taken Rajendra to Jammu for training in 2006.

Since Joshi was murdered in mysterious circumstances in December 2007, Rajendra's interrogation can lead investigators to the role played by the senior RSS functionary.

Witnesses have told investigators that Rajendra was missing from native place for eight to nine months in 2006. This time coincides with his alleged training period in Jammu.

The NIA has alleged that Rajendra along with three more accused - Kamal Chauhan, Lokesh Sharma and Amit alias Ashwini Chauhan - planted four IEDs in Samjhauta Express on February 18, 2007 killing 68 people, most whom were Pakistanis.

The NIA was looking for him for the last two years. But his active hunt started after arrest of Kamal Chauhan in February this year who told investigators that Rajendra was one of the bomb planters.

Besides the Samjhauta train, Rajendra is also alleged to be a Mecca Masjid bomb planter.